Documentation of major pests and spectrum of pesticide usage for tea agroecosystems in Bangladesh

Tea is an economically important beverage crop in the world including Bangladesh. Tea-based agroforestry systems act as reservoir of ecosystem functions, but the use of conventional pesticides in tea production has caused many complications in Bangladesh. Using a survey questionnaire, we documented major tea pests and their management in 25 tea estates in the north-east region of Bangladesh from 2018 to 2019. Red spider mite (Oligonychus coffeae) occurs in all tea estates where propargite and quinazoline acaricides are mostly used. Tea mosquito bug (Helopeltis theivora), jassid (Empoasca flavescens), and aphids (Toxoptera auranti) were the major insect pests. Neonicotinoid and pyrethroid insecticides are frequently used against insect pests. Red root rot (Ganoderma philippii), leaf anthracnose (Colletotrichum spp.), dieback (Fusarium spp.), horse hair blight (Marasmius equicrinis) and red rust (Cephaleuros parasiticus) were the prominent diseases. Copper oxychloride, propineb, and azoxystrobin + tebuconazole fungicides are frequently used. Bon dhonia (Scoparia dulcis), uchunti (Ageratum conyzoides), sun grass (Imperata cylindrica), fern (Diplazium esculentum), and ghetu (Clerodendron infortunatum) are the dominant weed species. Glyphosate and 2,4-D Amine herbicides are mostly used. The insect and mite group causes 37.5% crop loss, followed by weeds (10.4%) and diseases (7.2%). Tea mosquito bug causes 15.3% crop loss, followed by the red spider mite (10.2%), thrips (5.9%) and caterpillar (6.1%). The tea planters heavily depend on synthetic pesticides for pest management. We contend that the use of ecofriendly biopesticides should be encouraged for tea pest management to prevent pesticide hazards and ensure sustainable tea production in Bangladesh.